Rand function

[Default99]

I'm trying to generate numbers between -1 and 1 using the rand() function so i can pass random values to the two members of N structs but the program prints the same values N times. Any advice?

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
struct Complex
{
    double x;
    double y;
};
int main ()
{
    int N,i,j,k;
    struct Complex *comp;
    printf("Enter N:\n");
    scanf("%d",&N);
       comp = malloc(N*sizeof(struct Complex));
    if (comp == NULL)
    {
        printf("Error! Out of memory");
        return 1;
    }


    for (j=0;j<N;j++){            
srand ( time ( NULL));


       (comp + j)->x = (double)rand()/RAND_MAX*2.0-1.0;  


       (comp + j)->y = (double)rand()/RAND_MAX*2.0-1.0;   
    }
    for (i=0; i<N; i++)
    {
        printf("\n%f\t%f",(comp + i)->x,(comp + i)->y);
    }
return 0;

[GReaper]

Use srand() only once, preferably at the beginning of your program. Don't call it repeatedly.